Going from Panama to Brazil???

Hello everyone!I'm am trying to find a way to go from Panama to Brazil via boat. I'd rather not take a plane because, from what I've seen, the airfare rates are not looking ideal for the moment.So - if anyone could respond to this with any suggestions about traveling from Panama to Brazil (or even Panama to South America) via bus and boat - that would be great. Of course the Darien Gap can't be crossed by a bus or car - but - hopefully there are some options out there.Thanks in advance!